[Xen-devel] [PATCH 4/6] libxl: events: Tear down SIGCHLD machinery on ctx destruction
We want to have no fd events registered when we are idle. Also, we should put back the default SIGCHLD handler. So: * In libxl_ctx_free, use libxl_childproc_setmode to set the mode to the default, which is libxl_sigchld_owner_libxl (ie `libxl owns SIGCHLD only when it has active children'). But of course there are no active children at libxl teardown so this results in libxl__sigchld_notneeded: the ctx loses its interest in SIGCHLD (unsetting the SIGCHLD handler if we were the last ctx) and deregisters the per-ctx selfpipe fd. * assert that this is the case: ie that we are no longer interested in the selfpipe. Signed-off-by: Ian Jackson Acked-by: Ian Campbell Tested-by: Ian Campbell Release-Acked-by: Konrad Rzeszutek Wilk --- tools/libxl/libxl.c |3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index a238621..8f06043 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -162,11 +162,12 @@ int libxl_ctx_free(libxl_ctx *ctx) while ((eject = LIBXL_LIST_FIRST(&CTX->disk_eject_evgens))) libxl__evdisable_disk_eject(gc, eject); +libxl_childproc_setmode(CTX,0,0); for (i = 0; i < ctx->watch_nslots; i++) assert(!libxl__watch_slot_contents(gc, i)); assert(!libxl__ev_fd_isregistered(&ctx->watch_efd)); libxl__ev_fd_deregister(gc, &ctx->evtchn_efd); -libxl__ev_fd_deregister(gc, &ctx->sigchld_selfpipe_efd); +assert(!libxl__ev_fd_isregistered(&ctx->sigchld_selfpipe_efd)); /* Now there should be no more events requested from the application: */ -- 1.7.10.4 ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH 4/6] libxl: events: Tear down SIGCHLD machinery on ctx destruction
On Thu, 2014-11-27 at 18:27 +, Ian Jackson wrote: > We want to have no fd events registered when we are idle. > Also, we should put back the default SIGCHLD handler. So: > > * In libxl_ctx_free, use libxl_childproc_setmode to set the mode to >the default, which is libxl_sigchld_owner_libxl (ie `libxl owns >SIGCHLD only when it has active children'). > >But of course there are no active children at libxl teardown so >this results in libxl__sigchld_notneeded: the ctx loses its >interest in SIGCHLD (unsetting the SIGCHLD handler if we were the >last ctx) and deregisters the per-ctx selfpipe fd. > > * assert that this is the case: ie that we are no longer interested >in the selfpipe. > > Signed-off-by: Ian Jackson Acked-by: Ian Campbell > --- > tools/libxl/libxl.c |3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c > index 12a1013..785253d 100644 > --- a/tools/libxl/libxl.c > +++ b/tools/libxl/libxl.c > @@ -162,11 +162,12 @@ int libxl_ctx_free(libxl_ctx *ctx) > while ((eject = LIBXL_LIST_FIRST(&CTX->disk_eject_evgens))) > libxl__evdisable_disk_eject(gc, eject); > > +libxl_childproc_setmode(CTX,0,0); > for (i = 0; i < ctx->watch_nslots; i++) > assert(!libxl__watch_slot_contents(gc, i)); > assert(!libxl__ev_fd_isregistered(&ctx->watch_efd)); > libxl__ev_fd_deregister(gc, &ctx->evtchn_efd); > -libxl__ev_fd_deregister(gc, &ctx->sigchld_selfpipe_efd); > +assert(!libxl__ev_fd_isregistered(&ctx->sigchld_selfpipe_efd)); > > /* Now there should be no more events requested from the application: */ > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] [PATCH 4/6] libxl: events: Tear down SIGCHLD machinery on ctx destruction
We want to have no fd events registered when we are idle. Also, we should put back the default SIGCHLD handler. So: * In libxl_ctx_free, use libxl_childproc_setmode to set the mode to the default, which is libxl_sigchld_owner_libxl (ie `libxl owns SIGCHLD only when it has active children'). But of course there are no active children at libxl teardown so this results in libxl__sigchld_notneeded: the ctx loses its interest in SIGCHLD (unsetting the SIGCHLD handler if we were the last ctx) and deregisters the per-ctx selfpipe fd. * assert that this is the case: ie that we are no longer interested in the selfpipe. Signed-off-by: Ian Jackson --- tools/libxl/libxl.c |3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 12a1013..785253d 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -162,11 +162,12 @@ int libxl_ctx_free(libxl_ctx *ctx) while ((eject = LIBXL_LIST_FIRST(&CTX->disk_eject_evgens))) libxl__evdisable_disk_eject(gc, eject); +libxl_childproc_setmode(CTX,0,0); for (i = 0; i < ctx->watch_nslots; i++) assert(!libxl__watch_slot_contents(gc, i)); assert(!libxl__ev_fd_isregistered(&ctx->watch_efd)); libxl__ev_fd_deregister(gc, &ctx->evtchn_efd); -libxl__ev_fd_deregister(gc, &ctx->sigchld_selfpipe_efd); +assert(!libxl__ev_fd_isregistered(&ctx->sigchld_selfpipe_efd)); /* Now there should be no more events requested from the application: */ -- 1.7.10.4 ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
